Irreversible alveolar bone resorption is a common sequela to loss of teeth and other dental treatments. Prognosis for implants and dentures becomes unreliable as the foundation of support, which is used to model the interface of the prostheses, shifts and effectively gives way, causing loosening, bacterial infiltration, and ultimately failure. The long-term objective of this research is to provide the basic science understanding of irreversible alveolar bone resorption to promote sustained integration of implants and prosthodontics and to improve product design, surgical technique, and clinical treatments. In order to achieve this goal, we must determine the mechanism of alveolar bone resorption. The logical assumption is that mechanics itself plays a dominant role, since resorption strongly correlates with mechanical changes. However, while alveolar bone resorbs under these circumstances, essentially basal bone does not, although it too lies in the load path of mastication. The goal of this project is to investigate the differences between avelolar and basal bone. Since the primary cell type considered responsible for the mechanobiology of bone is the osteocyte, our overall hypothesis is that alveolar and basal osteocytes respond differently to shear and compressive forces. Therefore, we are thus challenged to identify how osteocytes from these two regions are different in Aim 1 and how they respond differentially to changes in loading (shear and compressive forces in Aim 2). Results from this study will advance our understanding of the mandibular osteocytes and their role in health and disease. PUBLIC HEALTH RELEVANCE: With the aging of our society and the fact that some degree of periodontal disease effects 75% of the US adult population, understanding the differences in molecular and cellular pathways governing alveolar and basal bone degeneration is of paramount importance. Advancing this understanding in inherent differences in these two types of mandibular bone and their responses to mechanical stress will enhance the development of improved treatment modalities for dental care and bone loss.